Water, energy demand spotlights risk of human-induced quakes

Key Highlights:

• Over 700 human-induced earthquakes have been recorded globally in the last 150 years.
• Human activities like mining, groundwater extraction, large dams, tall structures, and fracking can induce seismic activity.
• A 6.3 magnitude quake in Koynanagar (1967) was linked to the Koyna dam water load.
• A 2021 study linked shallow earthquakes in Delhi-NCR to excessive groundwater extraction.
• Mullaperiyar dam in Kerala and regions like Palghar (Maharashtra) show signs of human-linked seismic disturbances.
• Climate change (rainfall variability, glacier melt) is an emerging factor modulating earthquakes.
• India has 56 fracking sites across six States, adding to the seismic risk.

Detailed Insights:

• Repeated loading/unloading of the crust due to human activity accumulates strain between tectonic plates, altering natural seismic behaviour.
• In Delhi-NCR, increased quakes between 2003–2012 coincided with rapid groundwater depletion; seismic activity reduced after water table stabilization post-2014.
• Delhi lies on multiple faultlines and in Seismic Zone 4, making it vulnerable even to moderate quakes (up to 5.5 magnitude).
• Gangetic plains, heavily reliant on groundwater for irrigation, face similar risks due to declining water tables.
• Koynanagar earthquake (1967) killed over 180 people and was linked to the Koyna dam's water overload.
• The U.S. has regulations for reservoir filling/emptying to avoid reservoir-induced earthquakes—India currently lacks such protocols.
• Fracking and hydropower extraction are energy methods that elevate seismic risk due to subsurface fluid dynamics.
• Rain-induced seismicity is observed in Palghar and Sahyadri due to stress redistribution from heavy rainfall.
• Climate change, by altering rainfall and glacier melt, modifies surface water loads, influencing tectonic stress.

Way Forward:

• Establish seismic regulations for dam construction and reservoir operations in seismically sensitive regions.
• Scientific groundwater management to balance extraction and recharge, especially in the Indo-Gangetic plains.
• Strengthen seismic monitoring networks in vulnerable regions like Palghar, Sahyadri, and NCR.
• Conduct mandatory seismic risk assessments before setting up large infrastructure or energy projects.
• Regulate fracking and hydrocarbon exploration, incorporating seismic risk mapping.
• Incorporate climate impact projections in seismic vulnerability assessments.

Scientific/Technical Concepts Involved:

• Human-Induced Earthquakes: Seismic events triggered by anthropogenic activities like dam loading, groundwater depletion, and fracking.
• Fracking (Hydraulic Fracturing): Injection of high-pressure fluid into rocks to extract fossil fuels, which can alter subsurface pressure.
• Reservoir-Induced Seismicity (RIS): Earthquakes caused by large reservoirs due to increased pressure and percolation of water into faults.
• Faultlines & Plate Deformation: Weak zones in the Earth's crust susceptible to stress accumulation and sudden release.
• Seismic Zones: Classification of areas based on earthquake susceptibility; Delhi lies in Zone IV (high risk).